COVER 2 DEFENSE: A GENERAL PRIMER

For years,  the NFL has widely been known as copycat league.  Modern day schemes evolve and vary week to week in hopes to countering specific offensive plays,  players,  and tendencies.  Modern day coaches who have achieved success have roots firmly embedded in coaching trees of past innovators.  Schemes such as Bill Walsh's West Coast Offense (WCO) have changed the way the game is played today.  But none may have shown as much wisdom and success as the defense of the 1970's Pittsburgh Steelers. 

After a history of losing and a combined zero career postseason wins for the franchise,  it prompted Art Rooney to make a decision that would forever change the direction the franchise was heading with the addition of head coach Chuck Noll in 1969.  After a rocky 1-13 start,  Noll began to overhaul the roster and coaching staff.  Of all the proclamations of the great past Steelers drafts and signings,  none could possibly be more valuable than the addition of then,  Georgia Tech head coach,  Bud Carson.  Carson developed and refined a style of defense at the collegiate level known as the Cover 2. 

The cover 2 defense is defined as 2 players manning the post snap safety positions whose responsibility is the last line of defense for an eleven man unit in pass coverage divided up into equal halves of the field.  The name "cover 2" is a technique of defending the pass,  otherwise known as scheme.  It is most often associated with the 4-3 defense because it is the base set its most commonly run from,  but the cover 2 scheme can be run from nearly any defensive formation.  The defense relies on disciplined players who possess above average speed and tackling ability who swarm to the ball and are sure tacklers because often one slipped tackle can result in a big gain.  In todays NFL the cover 2 is the most prevalent defense and continues to be refined by successful teams such as the Colts,  Bears,  and Buccaneers.  Indinapolis head coach Tony Dungy was a safety for the 1978 Pittsburgh Steelers directily attributes his defensive philosophies to those Carson implemented in his playing days,  specifically the 1975 playbook.  Dungy has since put his personal refinements on scheme in his days as the Tampa Bay head coach having modern day NFL'ers rename the defense as the Tampa 2.  Its no coincidence that the teams previously mentioned (Bears,  Bucs,  Colts) implement the defense as head coach Lovie Smith installed it with the Bears,  Dungy with the Colts,  and Dungy's defensive coordinator  Monte Kiffin remains in Tampa Bay. 

The Formation

Figure one takes us to the eye in the sky and shows the most common base formation of the cover 2 defense.  It begins with 4 down lineman consisting of 2 defensive tackles (DT) and 2 defensive ends (DE),  3 linebackers (LB),  2 conerbacks (CB),  and 2 safeties (S).  Each has a unique responsibility that differs against the run and pass alike. 

Figures 2 further explains the zone coverage responsibilities for LB's and secondary when an offense is attempting a pass play.  The 1st level of coverage responbility awarded to LB's and CB's splits the field into equal 1/5's across the entire field with assignments that range from the line of scrimmage up to and including 15 yards deep with the 2 remaining players in deep alignment as the safety valves with whose main responsibility is not to let a route runner behind them.  Modern day spinoffs that will be addressed later have the middle linebacker drop up to 20-30 yards in coverage in the deep middle with the safeties effectively turning the cover 2 (deep 1/2's) into cover 3 (deep 1/3's). 

As previously mentioned,  it takes unique players with unique skillsets to effectively play the defense. 

The Players

Defensive Tackles:
Two specific types of DT's are needed whose assingment differ from one another and different techniques and alignments make the two unique of one another also.  Defensive lineman in this formation usually play a one gap responsiblity where their main responsibility is to attempt to split 2 blockers while not giving up any ground and maintain assigned rush lanes. 

Figure one shows gap designations to clearly help define a DT rush responsibility in the run and pass game with A gap between Center and Guard, B gap between guard and tackle and so on.  Figure 2 is a technique scale showing where the player is to line up.  A "0" technique DT lines heads up on the center,  2 technique heads up on the guard and so on. The odd number designations have the player lining up in gaps such as a 3 technique player on the outside shoulder of a guard and a 5 techniqe player in the outside shoulder of the tackle. 

The 2 DT's aforementioned in this alignment are as follows:

Nose Tackle:  A tall bulky player in the desired 6'4" 310 lb range is utilized mainly as a run stuffer.  His alignment will normally be a "0" shade technique to the weak side (side opposite tight end).  This player must possess tremendous core strength to move an anchored blocker in the run game and pass protection as well as have long arms to raise them while rushing the passer in hopes of cluttering a QB's throwing lanes and batting down passes. 

Under tackle (3 technique):  This player,  as mentioned,  normally lines up in a 3 technique position on the strong side.  His role is greatly expanded from the nose tackle.  This player must be very athletic,  strong,  and agile at the same time.  He is responsible for his gap designation against the run but is also relied upon to apply the bulk of the interior pressure on the quarterback while maintaining his assigned rush lane.  By effectively pushing the pocket applying pressure and hopefully sacks,  he also shortens the depth of the pocket not allowing the QB to step up giving the outside rush more of a chance to reach the QB. 

3 technique DT's are some of the hardest players for NFL talent evaluators to find due to the fact that NFL big men are not always as athletic as takes to play this position.  The competition for their services is so great that these players,  when on top of their game,  demand some of the highest salaries in football.  A deep rotation of DT's (wave players) are also an asset as to keep these big men fresh for 60 minutes.

Defensive Ends:
In this defensive set,  the DE's are the pass rushers.  The players given the enviable job of grabbing headlines rushing the QB.  Different coaches employ differnent variations of the defense so the style of player they covet can vary.  Some coaches prefer DE's with a smaller body type who bring an explosively quick first step as an edge rusher to effectively beat tackles to the edge reaching the QB from the backside.  This style of player isnt always the adequate vs. the power run game and normally attempts to play the run on his way to reaching the QB as opposed to having a run first assignment. This is the desired body type in Dungy's new Tampa 2.   Other philosophies search for somewhat larger players who can equally play the run and rush the passer as well.  On the strong side,  the players usually have to beat a tackle and tight end alike to apply pressure so the strenght attained from the extra bulk helps to play stout at the point of attack.  Think Will Smith in (NO) or Aaron Kampman (Green Bay). 

Middle Linebacker (MLB):
Or "mike" backer as commonly referred to.  Again different cover 2 philosophies employ different types of players for this position.  It is commonly preferred to have players athletic enough to play both run and pass to effectively  call them a "3 down backer" where he is able to stay in the game in any situation.  This applies to all LB's in this scheme.  If the scheme only calls for the Mike to take short drops in coverage and man the underneath zone,  a run stuffer is preferred in the mold of Jeremiah Trotter.  On the other hand,  certain coaches prefer the mike backer to able to take the deep middle drops into the secondary creating the cover 3 defense as previously mentioned. This player must also be able to be stout in the run game with strength to fight off blockers as well as footwork sort throught trash at the point of attack to run down a ball carrier.  Good horizontal skilles are needed as this player must be a "sideline to sideline" player to be most effective ala Ray Lewis in his hey day.  The deep coverage responsibilities require this player to also show good agility and ball skills to be able to turn and run with tight ends on seam routes and the unenviable task of running with deep post patterns.  Brian Urlacher may have said it best when he described his pass coverage responsibility as:

"My primary purpose in that defense is to run straight down the field with a tight end and then come back to the huddle to congratulate the player that made the tackle".

 The depth of the drops the mike backer takes is first and foremost the biggest difference from a standard cover 2 to a Tampa 2 and the other players zone responsibilities that come with it.   The deeper drop will cause the underneath defenders to play a zone composed of 1/4's instead of 1/5's.

Weakside Linbacker (WLB):
The WLB,  or "Will" or "Jack",  is usually the most athletic backer on field.  The weakside designation is from his alignment to the opposite side of an unbalanced set.  His primary responsibility in the run game is back side pursuit where he must be disciplined enough not overrun plays and be accountable for cutback lanes.  His pass coverage assignment is usually an 8-12 yard zone in attempts to discourage WR's and TE's from running underneath crossing routes..

Strongside Linebacker (SLB):
The SLB,  or Sam,  is the backer that lines up to the strong side of the offensive formation with very similar coverage responsibilities the WLB.  His run responsibility will differ a bit as offenses tend to run toward the strong side more often than not.  This requires a strong player who can at times line up on the line of scrimmage and fight off blocks from TE's and lead backs.   Taller players with longer wingspans are preferred to disengage from NFL caliber tackles.

Cornerbacks (CB):
This is where is gets tricky because its not always easy to find a CB with every desired skill to play the position.  Since the cover 2 plays mostly zone coverage,  the skillset needed includes good ball skills, good footwork,  and tough in run support.  Also,  great straight line speed isnt a necessity to play this zone coverage. The main focus in pass coverage is a 1/5 15 yard zone responsible for the flats and intermediate out patterns.  His objective is to keep everything in front of him in his zone until its stretched to the point where he must pass the receiver off to a safety.  In run support this player is responsible for outside contain and taking out lead blockers to string runners out to the sidelines.

In man coverage,  different,  or at least additional skillsets are needed.  This type of coverage requires the player to be able to run stride for stride with a receiver so the draft day terms we hear such as "loose hips" to be able to turn on a dime and run,  and 40 yard dash (straight line speed) apply here.  

Safety (S):
This position is what defines the cover 2 philosophy.  These players must be rangy with good speed and ball skills with the ability to play a 25 yard wide zone in their deep assignments.  As will be addressed later,  a huge soft spot in the zone is between the safeties so these players must be able to apply the big hit when needes to discourage route runners from re-entering their zone. 

Blitz Packages:
The cover 2 was designed for all the pressure to be applied by the 4 down lineman so all other defenders can play zone coverage.  Football is situational so every coach has an arsenal of blitzes unique to his scheme and players which are derivatives of others schemes. 

Examples could be DL stunts,  CB blitz,  LB blitz,  or safety blitz.  A variety of combination of any of these can be utilized but the more players asked to blitz,  the more holes that are created in the zone causing to the defensive secondary remaining to heavily rely on immediate pressure from the blitz package.  This is why it was mentioned in the player description of why it is so necessary to have quality DL to apply pressure with only 4.

Coverage:
As described earlier,  cover 2 is 2 safety valves each responsible for halves in deep coverage and the man that enters that specific zone by not allowing a receiver behind him.  2 general types of coverages are used.

Zone Coverage:

this diagram shows a nice breakdown of zone responsibilities for each player and where the "soft spots" lie that offenses will usually try and attack.  The prevalance of the Tampa 2 and the Mike backer taking a deep drop effectively helps eliminate that soft spot shown deep middle in blue in the diagram.  Which still leaves the deep sideline patterns as the remaining soft spots.  The effective use of Cover 4,  or quarters,  has become much more prevalent in todays NFL.  It allows a defense to pinch its safety play and help eliminate the soft spot (in blue) over the top in the center of the defense.  It helps hide inadequate safety play by having the CB's play with cushion and chasing after routes down their respective sideline still having safety help over the top.  The cover 4 style of play relies on pass rush from the front 4,  LB's cutting off underneath routes up the seam,  a converging secondary swarming to the ball.

With the 5 underneath defenders across the field,  coaches with utilize "inside out" bracket coverages meaning a player is responsible for a receiver and will run with him until he reaches the edge of his zone responsibility until the next zone defender in succession picks that man up.

Man to Man coverage:
Certain schemes will also employ this technique as each defender designated will have a specific man to cover.  Normally,  the desired coverage is called Man Under meaning the underneath defenders have man coverage while the safeties still have deep over the top zone assignments.  This idea is where cover 2 teams run the majority of their blitz packages.  It is used most often counteract an offense looking for holes in zones to create confusion and play break down.

Pattern Reads:
offense are always trying to attack soft spots on defense in attempt to move the ball.  This has caused the cover 2 defense to develop on-the-fly basic scheme changes known as pattern reads.  A pattern read is the ability of a defense,  through coaching and film study,  to immediately recognize where the offense plans to attack and adjusting accordingly. For example,  if a deep sideline route is being run to the blue soft spot shown on the diagram,  the CB must instantly play man coverage to assist the deep safety until he is able to get there to make a play.  What this does is run the CB out of his zone leaving that portion of the field wide open.  A pattern read adjustment would cause the WLB or SLB,  depending on the side,  to recongnize it and make a pattern read adjustment extnending his zone to the area of the vacated CB.  This is where defensive philosophies become complicated and what makes each coach unique.  This offensive strategy is known as a "hi/low stretch" which will be discussed later on. 

Zone Blitz:
the zone blitz is a call that will blitz one of the designated coverage defenders and drop one of the four down lineman back into the blitzers vacated short zone in attempts to confuse blockers and QB's.  This heavily relies on the athleticness of the lineman pass rushing ability of LB's. 

How to attack a Cover 2 defense:

1. Hi/Low stretch: - as previously mentioned its design is to run off an edge defender and then flood his vacated zone with other receiving targets such as a RB out of the backfield or a TE on a short arrow route. 
2. 4 vertical wide receivers: - when facing a cover 2 defense,  one of the first things an offense will do is test it deep to see how they will react as per the gameplan with the players on the field.  Any slip up or missed assignment could result in a big gain or touchdown.  To combat this CB's must attempt to flatten WR routes with a jam effectively forcing the receiver to run a crossing route as opposed to a free release off the line of scrimmage for him to get vertical.  Also,  it forces the LB's run get vertical with the TE's and RB's attempting seam routes as to aid the safeties shadowing the other deep receivers. 
3. In-out stretch: -  the same principle as the hi-low stretch but in a horizontal fashion.  As mention earlier,  a CB must jam a WR to prevent him from running a deep route up the sideline.   But once the WR does get free,  he'll run an out pattern stretching the CB to the sideline with creating an even wider void between the CB and either SLB or WLB in the zone.